The changing family roles and evidence that most infants form attachment relationships with both of their parents have sparked a debate about parenting arrangements when the parents of infants and toddlers separate. Misunderstanding of attachment theory and the available empirical evidence has obscured rather than clarified evidence-based decision-making. In this report, I closely examine the five studies most frequently referenced in this context and show what they do and do not tell us about the ways in which children’s adjustment can be promoted when their parents separate. Consistent with attachment theory, the evidence suggests that children benefit when parenting plans allow them to maintain meaningful and positive relationships with both of their parents